Anti-inflammatory effect of selagin-7-O-(6''-O-acetyl-)-ß-D-glycoside isolated from Cancrinia discoidea on lipopolysaccharide-induced mouse macrophage RAW 264.7 cells

Selagin-7-O-(6''-O-acetyl-)-ß-D-glycoside, a new flavone glycoside isolated from Cancrinia discoidea, is known to exhibit anti-inflammatory activity in vivo. This study aimed to investigate the protection of this flavone glycoside on inflammation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The effects of selagin-7-O-(6''-O-acetyl-)-ß-D-glycoside on inflammatory cytokines and signaling pathways were analyzed by enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, and western blot. Results show that selagin-7-O-(6''-O-acetyl-)-ß-D-glycoside protected LPS-induced macrophage RAW 264.7 cells from injury. The flavone glycoside markedly inhibited the LPS-induced production of tumor necrosis factor-α, interleukin-1ß, and interleukin-6 and increased interleukin-10 release in a concentration-dependent manner. Furthermore, treatment with the flavone glycoside decreased nitric oxide and prostaglandin E2 in LPS-challenged RAW 264.7 cells. These decreases were associated with the down-regulation of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), and nuclear factor kappa B (NF-κB) activity. These findings suggest that the anti-inflammatory effects of selagin-7-O-(6''-O-acetyl-)-ß-D-glycoside were associated with the adjustment of inflammatory cytokines, and attributed to the down-regulation of NF-κB and consequent suppression of the expression of iNOS and COX-2.